LTC3444 Micropower Synchronous Buck-Boost DC/DC Converter for WCDMA Applications

The LTC®3444 is a highly efficient, fixed frequency, buckboost DC/DC converter, which operates from input voltages above, below, and equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for a single Lithium-Ion or multi-cell applications where the output voltage can vary over a wide range.

The LTC3444 has been optimized for use in 3G WCDMA applications. A unique design yields high efficiency at very low output voltages while also eliminating external components. The high speed error amplifier provides the fast transient response required to slew the RF power amplifier from standby to transmit and transmit to stand by power levels. Output overvoltage protection protects the RF power amplifier.

Operating frequency is internally set to 1.5MHz to minimize external component size while maximizing efficiency. Other features include <1μA shutdown current, internal soft-start, peak current limit and thermal shutdown.

The LTC3444 is available in a small, thermally enhanced 8-lead (3mm × 3mm) DFN package

产品特点 Features

Optimized Features for WCDMA Handsets
Regulated Output with Input Voltages Above, Below, or Equal to the Output
0.5V to 5V Output Range
Up to 400mA Continuous Output Current From a Single Lithium-Ion Cell
Minimal External Components
1.5MHz Fixed Frequency Operation
Internal Loop Compensation for Fast Response <25μs Full Scale Output Slewing; COUT 4.7μF
Output Disconnect in Shutdown
2.75V to 5.5V Input
<1μA Shutdown Current
Internal Soft-Start
Output Overvoltage Protection
Single Inductor, No Schottky Diodes Required
Small, Thermally Enhanced 8-Lead (3mm × 3mm) DFN Package

应用

WCDMA Applications–3G Handsets with High Speed Data Rate Capability
MP3 Players
Digital Cameras

典型应用图

参数

LTC3444 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC3444EDD	DFN	8	E	$3.43	$2.40
LTC3444EDD#PBF	DFN	8	E	$3.43	$2.40
LTC3444EDD#TR	DFN	8	E		$2.46
LTC3444EDD#TRPBF	DFN	8	E		$2.46

LTC3444 数据手册及相关资料下载

数据手册(英文) : LTC3444 - Micropower Synchronous Buck-Boost DC/DC Converter for WCDMA Applications.PDF
设计要点 (英文) : Design Solutions 10 - Active Voltage Positioning Reduces Output Capacitors.PDF
可靠性数据 : R415 Reliability Data .PDF